/*
 * SVG Salamander
 * Copyright (c) 2004, Mark McKay
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 *   - Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the following
 *     disclaimer.
 *   - Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials 
 *     provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE. 
 * 
 * Mark McKay can be contacted at mark@kitfox.com.  Salamander and other
 * projects can be found at http://www.kitfox.com
 *
 * Created on April 1, 2004, 6:41 AM
 */

package com.kitfox.svg.composite;

import java.awt.CompositeContext;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;

/**
 * @author Mark McKay
 * @author <a href="mailto:mark@kitfox.com">Mark McKay</a>
 */
public class AdobeCompositeContext implements CompositeContext {
	final int compositeType;
	final float extraAlpha;

	float[] rgba_src = new float[4];
	float[] rgba_dstIn = new float[4];
	float[] rgba_dstOut = new float[4];

	/** Creates a new instance of AdobeCompositeContext */
	public AdobeCompositeContext(int compositeType, float extraAlpha) {
		this.compositeType = compositeType;
		this.extraAlpha = extraAlpha;

		rgba_dstOut[3] = 1f;
	}

	@Override
	public void compose(Raster src, Raster dstIn, WritableRaster dstOut) {
		int width = src.getWidth();
		int height = src.getHeight();

		for (int j = 0; j < height; j++) {
			for (int i = 0; i < width; i++) {
				src.getPixel(i, j, rgba_src);
				dstIn.getPixel(i, j, rgba_dstIn);

				// Ignore transparent pixels
				if (rgba_src[3] == 0) {
					// dstOut.setPixel(i, j, rgba_dstIn);
					continue;
				}

				float alpha = rgba_src[3];

				switch (compositeType) {
				default:
				case AdobeComposite.CT_NORMAL:
					rgba_dstOut[0] = rgba_src[0] * alpha
							+ rgba_dstIn[0] * (1f - alpha);
					rgba_dstOut[1] = rgba_src[1] * alpha
							+ rgba_dstIn[1] * (1f - alpha);
					rgba_dstOut[2] = rgba_src[2] * alpha
							+ rgba_dstIn[2] * (1f - alpha);
					break;
				case AdobeComposite.CT_MULTIPLY:
					rgba_dstOut[0] = rgba_src[0] * rgba_dstIn[0] * alpha
							+ rgba_dstIn[0] * (1f - alpha);
					rgba_dstOut[1] = rgba_src[1] * rgba_dstIn[1] * alpha
							+ rgba_dstIn[1] * (1f - alpha);
					rgba_dstOut[2] = rgba_src[2] * rgba_dstIn[2] * alpha
							+ rgba_dstIn[2] * (1f - alpha);
					break;
				}
			}
		}
	}

	@Override
	public void dispose() {
	}

}
